Primary healthcare units by regional health administrations in the Portuguese National Health Service sampled for the study of preventive health services implemented by primary healthcare physicians
| Number of primary healthcare units in the Portuguese National Health Service | Number of primary healthcare units (clusters) selected for our sample | |
|---|---|---|
| Northern regional health administration | 381 | 38 |
| Centre regional health administration | 65 | 6 |
| Lisbon and Tagus Valley regional health administration | 380 | 38 |
| Alentejo regional health administration | 57 | 6 |
| Algarve regional health administration | 19 | 2 |
| Total | 902 | 90 |